Control of the size and distribution of residual macronapples by rolling rollers

Abstract. To increase the fatigue strength of parts, surface plastic deformation (SPD) is used by rolling. This creates a residual stress state that affects the fatigue strength of parts. This paper shows the possibility of controlling the level and distribution of residual macrostresses in the surface layer of parts by rolling. This makes it possible to optimize the modes of PPD for critical, heavily loaded parts subjected to cyclic loads during operation. Problem. Controlling the magnitude and distribution of residual macro-stresses, which will increase their stability during cyclic loading of parts and, as a result, increase the fatigue strength of parts after hardening of the PPD. Goal. Study of the formation of residual stress state and control of the magnitude and distribution of residual macro-stresses. Methodology. To solve this problem, macrostresses were determined by the X-ray method. The advantage of this method is its localization, the ability to analyze the distribution of residual stresses in depth. It is the use of this advantage of the method that made it possible to identify features in the distribution of residual stresses on the surface and in the depth of the hardened layer of parts after rolling. Originality. The ability to control the level of residual stresses in the surface layer. Practical value. By changing the pumping modes, it is possible to ensure the required level of residual stresses on the surface and create the required residual stress distribution pattern over the depth, there by increasing the efficiency of the SPD.